The present invention relates generally to the field of server power management, and more specifically, to the power and energy management of server systems with multiple processor cores.
Server systems typically include a plurality of processor cores. Some server systems may license a predetermined number of processor cores depending on the expressed needs of the customer and further include spare processor cores that may be left inactive and unlicensed until the customer's needs increase, or until the spare is used as a replacement in the event of a failure of another core.
Many server systems are equipped with power, thermal, and energy management features such as dynamic voltage and frequency scaling (DVFS). It is known for server systems to run processor cores at various frequencies where a processor frequency comprises a base value and a multiple of a certain frequency step value. The voltage level may be adjusted in concert with the frequency. The frequency scaling of the processors affects the server's performance and power consumption. Dynamic frequency and voltage scaling allows power and performance optimizations tailored to workload, user preferences, power constraints, and other factors. During normal operation, maximum performance is obtained by operating the processors of the server at the maximum frequency designated by the server manufacturer. Lower power consumption may be obtained by operating the processors of the server at frequencies less than maximum frequencies.
As can be seen, there is an advantage for a method and system that manages power resources in a server system by varying frequency and voltage of the licensed processor cores.